Inclination sensors and transducers have broad applications in earth-moving, pavement management, and other construction equipment. Along with providing information for control of the mainframe of the equipment, the inclination sensors can provide feedback for the inclination or control of the machine tool, bucket, or blade, etc. The accuracy of the output of the sensor may be affected by variations in the gain and offset of the sensor's electronics, the linearity of the sensor, or the alignment of the sensor in the sensor package.
Inclination sensors based on fluid transducers have long been utilized, but are subject to cross axis errors caused by a change in the rotation of the fluid within the sensor's cross section. Because a slope control system operates with as much accuracy as can be achieved, typically a few hundredths of a degree, these errors are significant often 5 to 20 percent of the measurement. These errors generally increase with the magnitude of the cross axis inclination.
In recent years solid state microstructures have sometimes been used in place of fluid transducers. With such sensors, sensor alignment errors can be introduced during manufacturing. The main source of error results when, due to a cross axis deviation, the primary sensor is oriented at a +/-degree of rotation relative to the desired or primary plane of measurement.
Other sources of error may be due to various factors, including variations of temperature.
In U.S. Pat. No. 5,731,761 issued to the assignee of the present application, an inclination sensor is disclosed that includes an oven, a resistive element attached to the oven, an inclination transducer mounted in the oven, and a thermistor mounted to the oven, the purposes of which components are to compensate and correct for errors arising due to variations in temperature. The thermistor produces a signal representative of the actual temperature of the oven. A microprocessor receives the actual temperature signal of each inclination device and produces a heating signal to energize resistive elements to control the temperature of the respective ovens to a desired temperature. Such patent teaches a method to compensate for errors in inclination sensors due to temperature.
It would be desirable if there were provided an inclination sensor that could correct for errors due to temperature, vibration, misalignment and other factors that the sensor might be subjected to.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.